Device for switching-in and disconnecting signal apparatus



Fab 5 19%,, TscHuMa v 9 3 DEVICE FOR SWITCHING IN AND DISCONNEfiTING SIGNAL APPARATUS Filed May 12, 1944 Iizveizibr 0, T5612, mm!) Patented Feb. 5, 1946 2,394,275 onvi on 110R, swIroiniIe-In AND DIS- ooNNEoTmo SIGNAL APPARATUS Otto 'Ischumi, Soleure, Switzerland, assignor to Autophon Aktiengesellschaft, Soleure, Switzerland, a joint-stock company of Switzerland Application May 12, 1944, Serial No. 535,296 In Switzerland December 4, 1942 Claims.

This invention relates to devices for switchingin and disconnecting signal apparatus. In devices of this kind known up to date, switching-in and disconnecting a signal apparatus require a short-period operation of a switch specially provided for this purpose.

The device according to the invention remedies this inconvenience. It is of the kind comprising a dial for calling the subscribers and is characterised in that the switching-in and disconnecting is caused by operating the dials sparking and impulse contacts necessary for calling the subscribers. Owing to this feature no additional switching elements are necessary in that both the sparking contact and the impulse contact, in spite of their additional use, are in no way prevented from fulfilling their original purpose.

The accompanying drawing illustrates, by way i of example, one embodiment of the object of invention.

Fig. 1 is a diagram of this example and Fig. 2 shows a callin dial with special characters.

The signal apparatus N shown in Fig. 1 may be an acoustic means of communication with loud-speaker and microphone, or a teletype transmitting and receiving apparatus, etc. This apparatus N is connected by means of the terminals i and 2 with the installation over which the connections are to be established. Between the terminal 2 and the signal apparatus N the calling dial NS with the impulse contact 2 and the sparking contact is is switched-in. The sparking contact k is in single-pole connection with the impulse contact 2. In Fig. 1 this sparking contact lc bridges-over the signal apparatus N; this fact, however, is not an essential feature of the invention, for it might, with the same elTect, just as well be connected-in at the place a. Between the terminal I and the signal apparatus N lies the relay R with the contacts 1'1 and T2, the latter. controlling the optical signal SZ. Contact T1 is bridged-over by the condenser C.

If the apparatus is to be disconnected by the subscriber himself, the calling dial NS illustrated in Fig. 2 is rotated with the finger in the hole of the first figure to be dialled. Thereby, the sparking contact k is closed, whereby a current circuit is formed going from a power source connected to the terminal I over the relay R, sparking contact 7c, impulse contact 2, to the terminal 2 and from here back to the power source. Relay R comes into action and closes the contacts 11 and T2 with the effect that, on the one side, a circuit apparatus N--contact r1-impulse contact 2'- terminal 2, whereby the signal apparatus Nis connected-in while, on the other side, this operating condition is indicated by a flashing-up of the optical signal SZ. The calling dial can now be let go and the device remains ready for selection owing to the position of contact m.

If the apparatus is remote-controlled, an alternating current impulse reaches the relay R over the condenser C and the contact 11, thereby rendering possible the same operations as if the subscriber himself would have controlled the apparatus.

Should it be expected that between the moment of the switching-on and the selection readiness there would be an undesirably great time interval,'it is suitable to effect the switching-on by dialling the character E specially provided for this purpose, instead of dialling the first figure to be selected. By dialling the character E the sparking contact is is short-circuited, however, without impulses being given during the movement of the dial. Finally, the disconnecting process is begun by dialling the special character A. Dialling this character causes the opening of the impulse contact 2, which opening continues even during the return movement of the dial until the sparking contact is is open. Thereby the current in the relay R is interrupted, contact 71 drops back and the signal apparatus N is disconnected.

Furthermore, the arrangement according to which the switching-in of the signal apparatus is caused merely by dialling the first figure necessary for the connection desired has the very important advantage that the holding time of the station is considerably reduced in that the subscriber must first realise which figures are to be dialled before he can begin the connecting process.

What I claim is:

1. In an installation, a signal apparatus, and a device for switching-in and disconnecting said signal apparatus, comprising a dial including a sparking contact and an impulse contact necessary for calling the subscribers, said signal apparatus being arranged so that its switching-in and its disconnecting is caused by operating said sparking contact and said impulse contact.

2. In an installation according to claim 1, said signal apparatus being arranged so that its disconnecting is caused by dialling' the first figure of the subscribers number to be selected.

3. In an installation, a signal apparatus, a deis established over terminal l-relay Rsignal vice for switching-in and disconnecting said signal apparatus, comprising a dial including a sparking contact and an impulse contact necessary for calling the subscribers, said signal apparatus being arranged so that its switching-in and its disconnecting is caused by operating said sparking contact and said impulse contact, a direct current circuit able to establish the readi ness for selection, and means destined to indicate to the selecting subscriber the closing of said direct current circuit.

4. In an installation, a signal apparatus, a device for switching-in and disconnecting said signal apparatus, comprising a. dial including a sparking contact and an impulse contact necessary for calling the subscribers, said signal apparatus being arranged so that its switching-in and its disconnecting is caused by operating said sparking contact and said impulse contact, a direct current circuit able to establish the readiness for selection, and an optical signal destined 

